Unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
In implementing an optical communication system, alignment of an optical element such as a light-emitting element with another optical element such as an optical waveguide may be required. In such system, the light-emitting element such as a semiconductor laser or an LED (light-emitting diode) may serve as a source for generating optical communication signals while the optical waveguide serves as a channel for optical signal propagation. Accordingly, precise alignment of the light-emitting element with the optical waveguide may be important for providing a high speed and quality communication performance with minimal light propagation loss.
Some methods for alignment of a light-emitting element with an optical waveguide have been developed for practical use. In this example method, individual optical elements can be mounted by a machine manipulator at predetermined positions on a substrate which has been machined with high-precision machining process or MEMS (micro-electro-mechanical systems) process. Due to the limitation of machining precision and mechanical manipulation precision (which is typically on the order of about a few micrometers), precision of alignment may also be limited to a micron order. Thus, this example method may not be applicable to high-precision alignment at a submicron level.
In another example method, alignment of a light-emitting element with an optical waveguide can be controlled based on a result of performing optical detection, e.g., checking whether the optical performance satisfies desired characteristics, Since the precision of alignment in this method depends on optical detection accuracy, alignment for a submicron level precision may be achieved by fine-tuning a control system for optical detection. However, each alignment operation may require an optical detection operation, resulting in increase of the entire manufacturing costs.
As described above, with the conventional optical element alignment methods, it may be difficult to perform alignment operations in such a way that both high quality and low cost requirements are met. However, in some cases, there may be demands for aligning and mounting optical elements with high precision and at low cost.